1. Field of the Invention
This invention relates generally to printing apparatus for recording letters and/or pictures on a printing medium, and particularly to laser printers for achieving high-resolution images.
2. Prior Art
Recently, various types of laser printers are generally used for recording images. In those conventional laser printers, a photosensitive drum on which a photoconductive layer is provided is used, and a laser beam is applied to the photosensitive drum.
However, since the photoconductive layer is functioned as a photosensitive member, a charging mechanism using a high voltage portion is provided therein, and the photoconductive layer has to be provided on the circumference of the photosensitive drum. Therefore, there are disadvantages that the structure of laser printers becomes complicate and expensive, and that a dangerous high voltage generator exists therein.